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Critical Del. I-495 bridge to stay closed through summer

WILMINGTON, Del. — The earliest that traffic could return to the damaged I-495 bridge over the Christina River is Labor Day, meaning commuters, truckers and other travelers are facing a summer without full access to the critical bypass.

WILMINGTON, Del. — The earliest that traffic could return to the damaged I-495 bridge over the Christina River is Labor Day, meaning commuters, truckers and other travelers are facing a summer without full access to the critical bypass.

A tentative timeline was announced Tuesday as transportation officials described $20 million plans to temporarily shore up the leaning bridge supports, before tackling permanent repairs to the foundation and replacing two sets of piers.

"This is the experts' best way of trying to thread that needle of how can we quickly and safely restore traffic, but also something that can be part of the permanent solution," Transportation Secretary Shailen Bhatt said.

If all goes well, motorists would return to the southbound side of the bridge around Labor Day, and to the northbound lanes in mid- to late September. The span has been closed between 12th Street and Terminal Avenue since June 2.

Pressure from shifting soils next to the bridge have deformed steel piles in the bridge's foundation and displaced them sideways, fracturing several concrete footings. Engineers say a likely culprit is a 55,000-ton mountain of dirt stockpiled next to the damaged piers.

The proposed solution is to build a new foundation beneath the weakened section of the bridge, drilling four shafts up to 140-feet deep around each damaged pier. The shafts — filled with reinforced concrete — will form a stable base for crews to jack up the piers and return them to its original alignment.

The Delaware Department of Transportation is limited in part by the materials, equipment and skills available during the height of the road-construction season and by the desire to restore traffic on the bridge as soon as safely possible, Bhatt said. The soft "Jello-like" soils in the area also pose a problem.

That's where New York is generously helping out: This week, contractors reconstructing the 3-mile-long Tappan Zee Bridge over the Hudson River north of New York City decided to divert materials custom made for the Tappan Zee project to Delaware.

This saves DelDOT the six to eight weeks it would take to fabricate steel "cages" that will reinforce 4-foot-wide shafts drilled into the ground, Bhatt said. The cages are en route from Oklahoma and Washington state, said engineer Greg Burkhart of the firm J.D. Eckman Inc.

"They have to replenish what they're giving to us, but they have plenty of it and won't need it for a few months," Burkhart said.

The drills and casings should hopefully arrive at the bridge site by Friday, Bhatt said.

"That's a great relief," he said. "Yes, we could have gone with the bid process. But because we had all the right people in the room, we have the equipment and the expertise on its way here now."

Map of I-495 bridge closure.
(Photo:
Dan Garrow/The News Journal
)

Bhatt noted there's risk that problems could arise during drilling that cause the repair process to be drawn out into the fall.

Another option described by engineers was taking down the affected section of the bridge and rebuilding it. That's not preferred as it would take six months to design and construct, and traffic couldn't be restored until January.

The quickest option — jacking up the southbound lanes —was also ruled out due to soft, "Jello-O"-like soils in the vicinity.

Bhatt said that those assessing the problem a day after the closing made it clear that an experienced contractor with a wide range of resources needed to be part of planning for the solution.

"They said we've got some ideas. We know what could happen, but what we don't want to is get too far down the design path and have a contractor come in and say 'I can't build this,'" Bhatt said.

Consultants said they had a company with experience in emergency bridge repairs across the region, and expertise in structural engineering and in geotechnical work.

"At that time, I didn't know they weren't a Delaware firm," Bhatt said. "I just knew there was a firm out there who could be in the room the next day."

The company chosen — J.D. Eckman Inc. of Atglen, Pa. — completed emergency repairs for the I-95 bridge over the Brandywine Creek after a jogger spotted a long crack in the span in 2003.

The same company carried out a multiyear jacking up of the entire I-95 viaduct in Wilmington to replace critical support parts, and a 48-hour replacement of a 15-foot-high column that had forced the shutdown of a 3-mile stretch of road.

Burkhart said his company respects the work of Delaware contractors, but brings a wide range of resources and experience to the project, including specialized equipment and eight licensed engineers on staff.

"If there's a jacking plan that needs to be done, I don't need to go out to a consultant," Burkhart said. "We have the guys in-house, and I can tell them to work 24-hours a day. Which has happened."

Bhatt said that he was aware of concerns about the agency's choice of a non-Delaware company, but also aware of the public's needs.

"I want to do everything that is right, but for the 90,000 people a day who are waiting for that road to be opened, they don't care about that," Bhatt said. "They just want that road opened."